not my favorite shirt design by a long shot, but as a tolkien fan, this write-up was one of the funniest i've seen in a long time.
Also: Sauren is a Maiar. You can call him a spirit, if you will, but he was only a spirit back before the world was created. Once in the physical world, both Maiar and Valar (the more powerful and more rare 'spirits' or 'gods') chose physical forms. Gandalf is also a Maiar, as are Sauruman and all the Balrogs (there used to be many, many more). Sauron just so happens to be one of the most powerful Maiar spirits, since he was the top officer of the Baddest Bad Guy ever, named Morgoth, who happened to be a Valar- and the MOST POWERFUL valar, at that. The story of defeating him took tens of thousands of years and is told in the book The Silmarillion, which in my mind is at least as good as the LOTR. 
James D. Brown